Maintenance questions
 

Ok,
Couple of quick questions.

Front end grease points. where should I be checking for routine maintenance and how often with the F-250 I have.

I don't think my injectors have ever been replaced, it's running fine but I've heard people say I should have them changed around 300K and I'm at 308K and some change.

On occasion my windows won't roll down and my radio will cut out at the same time, I know this is an electrical problem but is this common with the 99-03?

Any tips to extend the engine life and any common problems I should be on the look out for before they become big ones?

grease up front anywhere you see grease fittings. depends if aftermarket ball joints if you have them there (top and bottom both side, then are are some on the tie rods. just look around).
me personally, after my 10,000 engine bill last mth when my truck with 210k dropped an injector, i will be changing my injectors around 175k no matter what. cheaper than buying a new engine.
and your radio/window issue is not common. check wiring/ground, cant help you on that one much.
and run good oil, change often! happy trucking!

the radio? hmm ive actually seen this quite a bit in the 7.3's